The present invention relates to a milling cutter for chip removing machining and an indexable cutting insert according to the preambles of the appended independent claims.
A generally rectangular milling insert is previously known that has two active cutting insert corners, which are provided diagonally opposed on the main surface of the cutting insert. The main cutting edges extend along the long sides of the cutting insert and consequently the minor cutting edges extend along the short sides of the milling insert. Since the milling insert has two active cutting insert corners it is indexable twice.
A milling cutter is also previously known which comprises a milling cutter body that is provided with a number of indexable cutting inserts. Each indexable cutting insert comprises four main cutting edges and one minor cutting edge associated with each major cutting edge. In mounted position in the milling cutter body the indexable cutting insert has a positive axial rake angle and a positive radial rake angle. The indexable cutting insert is generally screw shaped along the extension of the main cutting edge.
It is desirable to provide a milling cutter of the above-captioned defined type and an indexable cutting insert adapted to this, the milling cutter being able to machine right-angled corners in a work piece to great cutting depths.
It is also desirable to develop the indexable cutting insert according to the present invention in such a manner that it becomes indexable four times during its life.
It is also desirable to develop the indexable cutting inserts according to the present invention such that a stable localization of the indexable cutting insert in the milling cutter body is made possible.
According to an aspect of the present invention, a milling cutter for chip removing machining comprises a milling cutter body with at least one insert pocket associated with an end of the milling cutter body, wherein an opposite end of the milling cutter body is shaped to cooperate with a tool attachment, an indexable cutting insert being secured in each cutting insert pocket, wherein each indexable cutting insert has two substantially identical main surfaces, wherein two side surfaces and two end surfaces extend between the main surfaces, each main surface comprising two cutting insert corners, each cutting insert corner comprising a main cutting edge and a minor cutting edge, wherein a part of each main surface comprises rake faces, wherein a part of each side surface and each end surface comprises clearance surfaces, the cutting insert having a height between the end surfaces, each main surface comprising an associated support surface, wherein a perpendicular distance from each main cutting edge on either one of the two main surfaces to a plane that coincides with the support surface on the other one of the two main surfaces increases in direction from the cutting corner defined by the main cutting edge to a crest proximate a half height of the indexable cutting insert.
According to another aspect of the present invention, an indexable cutting insert has two substantially identical main surfaces, wherein two side surfaces and two end surfaces extend between the main surfaces, each main surface comprising two cutting insert corners, each cutting insert corner comprising a main cutting edge and a minor cutting edge, wherein a part of each main surface comprises a rake face, wherein a part of each side surface and each end surface comprises a clearance surface, the cutting insert having a height between the end surfaces, each main surface comprising an associated support surface, wherein a perpendicular distance from each main cutting edge on either one of the two main surfaces to a plane that coincides with the support surface on the other one of the two main surfaces increases in a direction from the cutting corner defined by the main cutting edge to a crest proximate a half height of the indexable cutting insert.